Manual Payment Setup for silverstripe-omnipay

When using silverstripe-omnipay, any required Omnipay modules must be installed via composer.

composer require omnipay/manual

Then in your config file (typically mysite/_config/config.yml, or mysite/_config/payment.yml)

---
Name: payment
---
SilverStripe\Omnipay\Model\Payment:
  allowed_gateways:
    - 'Manual'